1. Field
The invention relates to medical monitoring technology and more particularly to a monitor for a device used in angioplasty.
2. State of the Art
Balloon angioplasty, technically referred to as percutaneous transluminal angioplasty, is a procedure performed by a cardiologist on a patient under local anesthesia to open arteries blocked with plaque or other fatty deposits. A catheter with a dilatable (inflatable or deflatable) balloon at or near its tip is threaded into and through an artery and to the stenotic region. The balloon is then inflated thereby compressing the plaque against and into the arterial wall. In this manner the vessel's interior diameter is widened to again permit sufficient flow of blood. This procedure is utilized in the peripheral arteries as well as the coronary arteries. A balloon catheter is described and illustrated in U.S. Pat. No. 4,519,403.
Typically, the balloon is inflated utilizing a fluid such as a mixture of equal parts of a contrast media and saline solution, which fluid exerts the dilation pressure. An inflation syringe assembly or device is utilized to deliver the inflation medium or fluid to the balloon as well as to provide the pressure needed for dilation. Continuous pressure readings can be obtained by having the inflation syringe assembly coupled in series to a pressure reading device such as a manometer.
It is important that the inflation syringe assembly not only deliver fluid and maintain the pressure but also, in particular, release the pressure rapidly when needed.
Typical quick-release syringe devices heretofore disclosed in the art include those described in U.S. Pat. Nos. 4,832,692 to Box et al., and 4,723,939 to Goodin et al. The Box device utilizes an external lever located above the syringe barrel to release a splined block which engages/disengages a threaded plunger rod. The Goodin device employs a threaded plunger rod which is engaged/disengaged by a rotatable locking knob. Actuation of these release mechanisms may require a change of hand position on the syringe assembly.
Additionally, for safe and effective operation of the inflation syringe, it is important that the user have knowledge of the pressure exerted by the inflation syringe and the time elapsed with the balloon in the inflated state. Thus, a pressure sensor is associated with a monitoring readout device which displays the pressure readings. Previous such readout devices have generally taken the form of a box-like device attached to the pressure sensor by a data communication cable, the box to be placed for the user's viewing. If the cable is short, the box adds clutter to the operating area adjacent the patient. Alternatively, if the cable is long so that the device may be placed away from the immediate operating area, the cable between the readout device and the syringe is cumbersome and may obstruct movement of medical personnel in the area proximal to the patient.
Additionally, many such monitors do not include a timer for keeping track of time elapsed during balloon inflation. The user must refer to a separate timekeeping device such as a watch, stopwatch or clock to keep track of elapsed time. Looking back and forth between the timekeeping device and the pressure display is inconvenient and may slow the user's reaction time in operating the syringe.
A need exists for a readout device for an angioplastic balloon catheter which can be remotely placed for viewing and provides a wireless transmission of data signals. A need further remains for such a monitor which includes a timekeeping display in a field of view adjacent to the pressure display.